#!/bin/bash
# Tetris Game
# 10.21.2003 xhchen<xhchen@winbond.com.tw>

#颜色定义
cRed=1
cGreen=2
cYellow=3
cBlue=4
cFuchsia=5
cCyan=6
cWhite=7
colorTable=($cRed $cGreen $cYellow $cBlue $cFuchsia $cCyan $cWhite)

#位置和大小
iLeft=3
iTop=2
((iTrayLeft = iLeft + 2))
((iTrayTop = iTop + 1))
((iTrayWidth = 10))
((iTrayHeight = 15))

#颜色设置
cBorder=$cGreen
cScore=$cFuchsia
cScoreValue=$cCyan

#控制信号
#改游戏使用两个进程，一个用于接收输入，一个用于游戏流程和显示界面;
#当前者接收到上下左右等按键时，通过向后者发送signal的方式通知后者。
sigRotate=25
sigLeft=26
sigRight=27
sigDown=28
sigAllDown=29
sigExit=30

#七中不同的方块的定义
#通过旋转，每种方块的显示的样式可能有几种
box0=(0 0 0 1 1 0 1 1)
box1=(0 2 1 2 2 2 3 2 1 0 1 1 1 2 1 3)
box2=(0 0 0 1 1 1 1 2 0 1 1 0 1 1 2 0)
box3=(0 1 0 2 1 0 1 1 0 0 1 0 1 1 2 1)
box4=(0 1 0 2 1 1 2 1 1 0 1 1 1 2 2 2 0 1 1 1 2 0 2 1 0 0 1 0 1 1 1 2)
box5=(0 1 1 1 2 1 2 2 1 0 1 1 1 2 2 0 0 0 0 1 1 1 2 1 0 2 1 0 1 1 1 2)
box6=(0 1 1 1 1 2 2 1 1 0 1 1 1 2 2 1 0 1 1 0 1 1 2 1 0 1 1 0 1 1 1 2)
#所有其中方块的定义都放到box变量中
box=(${box0[@]} ${box1[@]} ${box2[@]} ${box3[@]} ${box4[@]} ${box5[@]} ${box6[@]})
#各种方块旋转后可能的样式数目
countBox=(1 2 2 2 4 4 4)
#各种方块再box数组中的偏移
offsetBox=(0 1 3 5 7 11 15)

#每提高一个速度级需要积累的分数
iScoreEachLevel=50   #be greater than 7

#运行时数据
sig=0      #接收到的signal
iScore=0   #总分
iLevel=0   #速度级
boxNew=()   #新下落的方块的位置定义
cBoxNew=0   #新下落的方块的颜色
iBoxNewType=0   #新下落的方块的种类
iBoxNewRotate=0   #新下落的方块的旋转角度
boxCur=()   #当前方块的位置定义
cBoxCur=0   #当前方块的颜色
iBoxCurType=0   #当前方块的种类
iBoxCurRotate=0   #当前方块的旋转角度
boxCurX=-1   #当前方块的x坐标位置
boxCurY=-1   #当前方块的y坐标位置
iMap=()      #背景方块图表

#初始化所有背景方块为-1, 表示没有方块
for ((i = 0; i < iTrayHeight * iTrayWidth; i++)); do iMap[$i]=-1; done


#接收输入的进程的主函数
function RunAsKeyReceiver()
{
   local pidDisplayer key aKey sig cESC sTTY

   pidDisplayer=$1
   aKey=(0 0 0)

   cESC=`echo -ne "\33"`
   cSpace=`echo -ne "\40"`

   #保存终端属性。在read -s读取终端键时，终端的属性会被暂时改变。
   #如果在read -s时程序被不幸杀掉，可能会导致终端混乱，
   #需要在程序退出时恢复终端属性。
   sTTY=`stty -g`

   #捕捉退出信号
   trap "MyExit;" INT TERM
   trap "MyExitNoSub;" $sigExit

   #隐藏光标
   echo -ne "\33[?25l"


   while (( 1 ))
   do
      #读取输入。注-s不回显，-n读到一个字符立即返回
      read -s -n 1 key

      aKey[0]=${aKey[1]}
      aKey[1]=${aKey[2]}
      aKey[2]=$key
      sig=0

      #判断输入了何种键
      if [[ $key == $cESC && ${aKey[1]} == $cESC ]]
      then
         #ESC键
         MyExit
      elif [[ ${aKey[0]} == $cESC && ${aKey[1]} == "[" ]]
      then
         if [[ $key == "A" ]]; then sig=$sigRotate   #<向上键>
         elif [[ $key == "B" ]]; then sig=$sigDown   #<向下键>
         elif [[ $key == "D" ]]; then sig=$sigLeft   #<向左键>
         elif [[ $key == "C" ]]; then sig=$sigRight   #<向右键>
         fi
      elif [[ $key == "W" || $key == "w" ]]; then sig=$sigRotate   #W, w
      elif [[ $key == "S" || $key == "s" ]]; then sig=$sigDown   #S, s
      elif [[ $key == "A" || $key == "a" ]]; then sig=$sigLeft   #A, a
      elif [[ $key == "D" || $key == "d" ]]; then sig=$sigRight   #D, d
      elif [[ "[$key]" == "[]" ]]; then sig=$sigAllDown   #空格键
      elif [[ $key == "Q" || $key == "q" ]]         #Q, q
      then
         MyExit
      fi

      if [[ $sig != 0 ]]
      then
         #向另一进程发送消息
         kill -$sig $pidDisplayer
      fi
   done
}

#退出前的恢复
function MyExitNoSub()
{
   local y

   #恢复终端属性
   stty $sTTY
   ((y = iTop + iTrayHeight + 4))

   #显示光标
   echo -e "\33[?25h\33[${y};0H"
   exit
}


function MyExit()
{
   #通知显示进程需要退出
   kill -$sigExit $pidDisplayer

   MyExitNoSub
}


#处理显示和游戏流程的主函数
function RunAsDisplayer()
{
   local sigThis
   InitDraw

   #挂载各种信号的处理函数
   trap "sig=$sigRotate;" $sigRotate
   trap "sig=$sigLeft;" $sigLeft
   trap "sig=$sigRight;" $sigRight
   trap "sig=$sigDown;" $sigDown
   trap "sig=$sigAllDown;" $sigAllDown
   trap "ShowExit;" $sigExit

   while (( 1 ))
   do
      #根据当前的速度级iLevel不同，设定相应的循环的次数
      for ((i = 0; i < 21 - iLevel; i++))
      do
         sleep 0.02
         sigThis=$sig
         sig=0

         #根据sig变量判断是否接受到相应的信号
         if ((sigThis == sigRotate)); then BoxRotate;   #旋转
         elif ((sigThis == sigLeft)); then BoxLeft;   #左移一列
         elif ((sigThis == sigRight)); then BoxRight;   #右移一列
         elif ((sigThis == sigDown)); then BoxDown;   #下落一行
         elif ((sigThis == sigAllDown)); then BoxAllDown;   #下落到底
         fi
      done
      #kill -$sigDown $$
      BoxDown   #下落一行
   done
}


#BoxMove(y, x), 测试是否可以把移动中的方块移到(x, y)的位置, 返回0则可以, 1不可以
function BoxMove()
{
   local j i x y xTest yTest
   yTest=$1
   xTest=$2
   for ((j = 0; j < 8; j += 2))
   do
      ((i = j + 1))
      ((y = ${boxCur[$j]} + yTest))
      ((x = ${boxCur[$i]} + xTest))
      if (( y < 0 || y >= iTrayHeight || x < 0 || x >= iTrayWidth))
      then
         #撞到墙壁了
         return 1
      fi
      if ((${iMap[y * iTrayWidth + x]} != -1 ))
      then
         #撞到其他已经存在的方块了
         return 1
      fi
   done
   return 0;
}


#将当前移动中的方块放到背景方块中去,
#并计算新的分数和速度级。(即一次方块落到底部)
function Box2Map()
{
   local j i x y xp yp line

   #将当前移动中的方块放到背景方块中去
   for ((j = 0; j < 8; j += 2))
   do
      ((i = j + 1))
      ((y = ${boxCur[$j]} + boxCurY))
      ((x = ${boxCur[$i]} + boxCurX))
      ((i = y * iTrayWidth + x))
      iMap[$i]=$cBoxCur
   done

   #消去可被消去的行
   line=0
   for ((j = 0; j < iTrayWidth * iTrayHeight; j += iTrayWidth))
   do
      for ((i = j + iTrayWidth - 1; i >= j; i--))
      do
         if ((${iMap[$i]} == -1)); then break; fi
      done
      if ((i >= j)); then continue; fi

      ((line++))
      for ((i = j - 1; i >= 0; i--))
      do
         ((x = i + iTrayWidth))
         iMap[$x]=${iMap[$i]}
      done
      for ((i = 0; i < iTrayWidth; i++))
      do
         iMap[$i]=-1
      done
   done

   if ((line == 0)); then return; fi

   #根据消去的行数line计算分数和速度级
   ((x = iLeft + iTrayWidth * 2 + 7))
   ((y = iTop + 11))
   ((iScore += line * 2 - 1))
   #显示新的分数
   echo -ne "\33[1m\33[3${cScoreValue}m\33[${y};${x}H${iScore}         "
   if ((iScore % iScoreEachLevel < line * 2 - 1))
   then
      if ((iLevel < 20))
      then
         ((iLevel++))
         ((y = iTop + 14))
         #显示新的速度级
         echo -ne "\33[3${cScoreValue}m\33[${y};${x}H${iLevel}        "
      fi
   fi
   echo -ne "\33[0m"


   #重新显示背景方块
   for ((y = 0; y < iTrayHeight; y++))
   do
      ((yp = y + iTrayTop + 1))
      ((xp = iTrayLeft + 1))
      ((i = y * iTrayWidth))
      echo -ne "\33[${yp};${xp}H"
      for ((x = 0; x < iTrayWidth; x++))
      do
         ((j = i + x))
         if ((${iMap[$j]} == -1))
         then
            echo -ne "  "
         else
            echo -ne "\33[1m\33[7m\33[3${iMap[$j]}m\33[4${iMap[$j]}m[]\33[0m"
         fi
      done
   done
}


#下落一行
function BoxDown()
{
   local y s
   ((y = boxCurY + 1))   #新的y坐标
   if BoxMove $y $boxCurX   #测试是否可以下落一行
   then
      s="`DrawCurBox 0`"   #将旧的方块抹去
      ((boxCurY = y))
      s="$s`DrawCurBox 1`"   #显示新的下落后方块
      echo -ne $s
   else
      #走到这儿, 如果不能下落了
      Box2Map      #将当前移动中的方块贴到背景方块中
      RandomBox   #产生新的方块
   fi
}

#左移一列
function BoxLeft()
{
   local x s
   ((x = boxCurX - 1))
   if BoxMove $boxCurY $x
   then
      s=`DrawCurBox 0`
      ((boxCurX = x))
      s=$s`DrawCurBox 1`
      echo -ne $s
   fi
}

#右移一列
function BoxRight()
{
   local x s
   ((x = boxCurX + 1))
   if BoxMove $boxCurY $x
   then
      s=`DrawCurBox 0`
      ((boxCurX = x))
      s=$s`DrawCurBox 1`
      echo -ne $s
   fi
}


#下落到底
function BoxAllDown()
{
   local k j i x y iDown s
   iDown=$iTrayHeight

   #计算一共需要下落多少行
   for ((j = 0; j < 8; j += 2))
   do
      ((i = j + 1))
      ((y = ${boxCur[$j]} + boxCurY))
      ((x = ${boxCur[$i]} + boxCurX))
      for ((k = y + 1; k < iTrayHeight; k++))
      do
         ((i = k * iTrayWidth + x))
         if (( ${iMap[$i]} != -1)); then break; fi
      done
      ((k -= y + 1))
      if (( $iDown > $k )); then iDown=$k; fi
   done

   s=`DrawCurBox 0`   #将旧的方块抹去
   ((boxCurY += iDown))
   s=$s`DrawCurBox 1`   #显示新的下落后的方块
   echo -ne $s
   Box2Map      #将当前移动中的方块贴到背景方块中
   RandomBox   #产生新的方块
}


#旋转方块
function BoxRotate()
{
   local iCount iTestRotate boxTest j i s
   iCount=${countBox[$iBoxCurType]}   #当前的方块经旋转可以产生的样式的数目

   #计算旋转后的新的样式
   ((iTestRotate = iBoxCurRotate + 1))
   if ((iTestRotate >= iCount))
   then
      ((iTestRotate = 0))
   fi

   #更新到新的样式, 保存老的样式(但不显示)
   for ((j = 0, i = (${offsetBox[$iBoxCurType]} + $iTestRotate) * 8; j < 8; j++, i++))
   do
      boxTest[$j]=${boxCur[$j]}
      boxCur[$j]=${box[$i]}
   done

   if BoxMove $boxCurY $boxCurX   #测试旋转后是否有空间放的下
   then
      #抹去旧的方块
      for ((j = 0; j < 8; j++))
      do
         boxCur[$j]=${boxTest[$j]}
      done
      s=`DrawCurBox 0`

      #画上新的方块
      for ((j = 0, i = (${offsetBox[$iBoxCurType]} + $iTestRotate) * 8; j < 8; j++, i++))
      do
         boxCur[$j]=${box[$i]}
      done
      s=$s`DrawCurBox 1`
      echo -ne $s
      iBoxCurRotate=$iTestRotate
   else
      #不能旋转，还是继续使用老的样式
      for ((j = 0; j < 8; j++))
      do
         boxCur[$j]=${boxTest[$j]}
      done
   fi
}


#DrawCurBox(bDraw), 绘制当前移动中的方块, bDraw为1, 画上, bDraw为0, 抹去方块。
function DrawCurBox()
{
   local i j t bDraw sBox s
   bDraw=$1

   s=""
   if (( bDraw == 0 ))
   then
      sBox="\40\40"
   else
      sBox="[]"
      s=$s"\33[1m\33[7m\33[3${cBoxCur}m\33[4${cBoxCur}m"
   fi

   for ((j = 0; j < 8; j += 2))
   do
      ((i = iTrayTop + 1 + ${boxCur[$j]} + boxCurY))
      ((t = iTrayLeft + 1 + 2 * (boxCurX + ${boxCur[$j + 1]})))
      #\33[y;xH, 光标到(x, y)处
      s=$s"\33[${i};${t}H${sBox}"
   done
   s=$s"\33[0m"
   echo -n $s
}


#更新新的方块
function RandomBox()
{
   local i j t

   #更新当前移动的方块
   iBoxCurType=${iBoxNewType}
   iBoxCurRotate=${iBoxNewRotate}
   cBoxCur=${cBoxNew}
   for ((j = 0; j < ${#boxNew[@]}; j++))
   do
      boxCur[$j]=${boxNew[$j]}
   done


   #显示当前移动的方块
   if (( ${#boxCur[@]} == 8 ))
   then
      #计算当前方块该从顶端哪一行"冒"出来
      for ((j = 0, t = 4; j < 8; j += 2))
      do
         if ((${boxCur[$j]} < t)); then t=${boxCur[$j]}; fi
      done
      ((boxCurY = -t))
      for ((j = 1, i = -4, t = 20; j < 8; j += 2))
      do
         if ((${boxCur[$j]} > i)); then i=${boxCur[$j]}; fi
         if ((${boxCur[$j]} < t)); then t=${boxCur[$j]}; fi
      done
      ((boxCurX = (iTrayWidth - 1 - i - t) / 2))

      #显示当前移动的方块
      echo -ne `DrawCurBox 1`

      #如果方块一出来就没处放，Game over!
      if ! BoxMove $boxCurY $boxCurX
      then
         kill -$sigExit ${PPID}
         ShowExit
      fi
   fi



   #清除右边预显示的方块
   for ((j = 0; j < 4; j++))
   do
      ((i = iTop + 1 + j))
      ((t = iLeft + 2 * iTrayWidth + 7))
      echo -ne "\33[${i};${t}H        "
   done

   #随机产生新的方块
   ((iBoxNewType = RANDOM % ${#offsetBox[@]}))
   ((iBoxNewRotate = RANDOM % ${countBox[$iBoxNewType]}))
   for ((j = 0, i = (${offsetBox[$iBoxNewType]} + $iBoxNewRotate) * 8; j < 8; j++, i++))
   do
      boxNew[$j]=${box[$i]};
   done

   ((cBoxNew = ${colorTable[RANDOM % ${#colorTable[@]}]}))

   #显示右边预显示的方块
   echo -ne "\33[1m\33[7m\33[3${cBoxNew}m\33[4${cBoxNew}m"
   for ((j = 0; j < 8; j += 2))
   do
      ((i = iTop + 1 + ${boxNew[$j]}))
      ((t = iLeft + 2 * iTrayWidth + 7 + 2 * ${boxNew[$j + 1]}))
      echo -ne "\33[${i};${t}H[]"
   done
   echo -ne "\33[0m"
}


#初始绘制
function InitDraw()
{
   clear
   RandomBox   #随机产生方块，这时右边预显示窗口中有方快了
   RandomBox   #再随机产生方块，右边预显示窗口中的方块被更新，原先的方块将开始下落
   local i t1 t2 t3

   #显示边框
   echo -ne "\33[1m"
   echo -ne "\33[3${cBorder}m\33[4${cBorder}m"

   ((t2 = iLeft + 1))
   ((t3 = iLeft + iTrayWidth * 2 + 3))
   for ((i = 0; i < iTrayHeight; i++))
   do
      ((t1 = i + iTop + 2))
      echo -ne "\33[${t1};${t2}H||"
      echo -ne "\33[${t1};${t3}H||"
   done

   ((t2 = iTop + iTrayHeight + 2))
   for ((i = 0; i < iTrayWidth + 2; i++))
   do
      ((t1 = i * 2 + iLeft + 1))
      echo -ne "\33[${iTrayTop};${t1}H=="
      echo -ne "\33[${t2};${t1}H=="
   done
   echo -ne "\33[0m"


   #显示"Score"和"Level"字样
   echo -ne "\33[1m"
   ((t1 = iLeft + iTrayWidth * 2 + 7))
   ((t2 = iTop + 10))
   echo -ne "\33[3${cScore}m\33[${t2};${t1}HScore"
   ((t2 = iTop + 11))
   echo -ne "\33[3${cScoreValue}m\33[${t2};${t1}H${iScore}"
   ((t2 = iTop + 13))
   echo -ne "\33[3${cScore}m\33[${t2};${t1}HLevel"
   ((t2 = iTop + 14))
   echo -ne "\33[3${cScoreValue}m\33[${t2};${t1}H${iLevel}"
   echo -ne "\33[0m"
}


#退出时显示GameOVer!
function ShowExit()
{
   local y
   ((y = iTrayHeight + iTrayTop + 3))
   echo -e "\33[${y};0HGameOver!\33[0m"
   exit
}



#游戏主程序在这儿开始.
if [[ $1 != "--show" ]]
then
   bash $0 --show&   #以参数--show将本程序再运行一遍
   RunAsKeyReceiver $!   #以上一行产生的进程的进程号作为参数
   exit
else
   #当发现具有参数--show时，运行显示函数
   RunAsDisplayer
   exit
fi
